Apparatus for testing air.



W. s. LEI-10H. APPARATUS FOR TESTING AIB.

APPLIOATIOH FILED FEB. 4, 1910.

Patented Apr. 9, 1912.

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WALTER STUART LEECH, 0F IBROOTEN, MINNESOTA.

APPARATUS FOR TESTING AIR.

1 Specification of Letters Patent.

Application filed February 4, 1910. serial No. 542,120.

To all whom it may concern:

Be it known that I, WALTER STUART LEECH, a citizen of the United States,residing at Brooten, in the county of Stearns and State of Minnesota,have invented new and useful Improvements in Apparatus for Testing Air,of which the following is a specification.

My invention relates to improvements in air testing apparatus, and itsprimary object is the provision of a simple, durable and efficientdevice of this character by which the quantity of carbonic acid gas inthe atmosphere may be determined.

A further object of the-invention is the provision of an air tester ofthe above stated character which may be manufactured and sold at acomparatively low cost, and which shall be especially adapted fordomestic use.

With the above and other objects in view, my invention consists in theconstruction, combination and arrangement of parts hereinafter .fullydescribed and claimed, and illustrated in the accompanying drawing,wherein Figure 1 is a' view in front elevation of an air testerconstructed in accordance with my invention. Fig. 2 is a view in sideelevation thereof. Fig. 3 is a detail perspective view of the bracketarm supporting the lower end of the reservoir. Fig. 1 is a detailperspective View of the bracket shelf supporting the receptacle. Fig. 5is a sectional view taken on the plane indicated by the-line 55 ofFig. 1. Fig. 6 is a detail View in side elevation of a modified form ofreservoir. Fig. 7 is a sectional view illustrating the manner in whichthe liquid spreading member is secured in applied position. Fig. 8 is asimilar view illustrating a modified form of'liquid spreading member,and Fig. 9 is a view in side elevation illustrating a further modifiedform of liquid spreading member.

Referring to the drawing by reference numerals, 1 designates a bracketboard which is preferably oblong in form and which is provided at itsupper end with an opening 2, the opening permitting the air tester to besecured to a wall or other support through the medium of a nail. Areservoir 3 which'is secured to the front side of the bracket board 1adjacent the upper end thereof, is designed to contain a quantity ofcolored liquid which loses its color when subjected to the action ofcarbonic acid gas. The reservoir is preferably colored to prevent thelight from affecting the, colored liquid therein. The body 4 of thereservoir 3 is preferably cylindrical and has its upper end fully open.A cap 5 is removably applied tothe upper end of the body 4. The

lower end of the body 4 is contracted and Patented Apr. 9, 1912.

formed to provide a depending discharge.

nozzle 6. The flow of liquid from the reservoir 3 is under the controlof a turning plug 7 mounted in the discharge nozzle 6 and provided witha way 8 adapted to be brought into and moved out of registration withthe passage 9 of the discharge nozzle 6. The

reservoir 8 is secured to the bracket board 1 by a pair of springclamping arms 10 which are secured to the bracket board 1 and whichembrace the body 1 of the reservoir, and by a bracket arm 11 provided atits outer end with a fork 12 adapted to receive the nozzle 6 of thereservoir. The inner end of the bracket arm 11 is provided with a base13 perforated as at 14 to permit of the bracket arms attachment to thebracket board 1. The nozzle 6 of the reservoir 3 is secured in the-fork12 by a plate 15 which is removably secured to the outer ends of thefork by bolts 16. The construction of the means securing the reservoir 3to the bracket board 1 is such as to permit the reservoir 3 to bereadily and quickly removed and replaced. I

Situated at a point below the discharge end of the nozzle 6, to spreadthe liquid escaping from the reservoir 3 into a thin film, is a member17 which may beof'that form disclosed in Figs. land 2,'or of'that formdisclosed in Fig. 9. In view of the fact that it is spread out into athin film by the member 17, the liquid in its'passage from the reservoir3 to a receptacle 18 is tho-roughly acted upon by the atmosphere. If theatmosphere contains any carbonic acid gas the color of the liquid willbe changed, and the rapidity with which the liquid loses its colordetermines the quantity of carbonic acid gas in the atmosphere. Themember 17 may have a curved outer surface as shown in Figs. 1 and 2 oran angular outer surface as shown in Fig. 9, the only requisite beingthat it should terminate in a pointed lower end 19 and that the outersurface or surfaces thereof should converge to said point. The liquiddrops from the point 19 of the member 17 into the receptacle 18, and toretard the passage of the liquid from the member 17 to the receptacle 18an element 20 of wire or any other material is secured to the lower endof the member. The element 20 is carried by a stem 21 secured in asocket 22 formed in the lower end of the member 17 The member 17 isconstructed of malleable material and it is secured to the front side ofthe bracket board 1 by a bolt 23 which has a head 24 embedded in themember. The receptacle 18 is mounted upon a bracket shelf 25 secured tothe front side of the bracket board 1. The bracket shelf comprises avertical base plate 26 provided with openings 27 for the passage offastening screws 28 and a horizontal supporting shelf 29. The shelf 29is provided with grooves 30 adapted to receive a flange 31 formed uponthe lower end of the receptacle 18, said flange being shown in dottedlines in Fig. 1 of the drawing. The grooves 30 open out through thefront edge of the shelf 29, and the receptacle 18 is secured upontheshelf 29 through the medium of a plate 32 which is removably secured inapplied position by bolts 33. Located below the member 17 and above thereceptacle 18 is a retarding element inthe form of a cup 34 whichreceives the liquid dropping from the member 17. The cup 34 is providedin its side with an overflow opening 35 through which the overflow ofliquid in the cup 34 passes into the receptacle 18. The cup 34 issupported in applied position by a bracket 36.

In practice the receptacle 3 is supplied with a quantity of coloredfluid which will lose its color on being subjected to the action ofatmosphere containing carbonic acid gas. The plug 7 is then turned toregister its way 8 with the passage 9 of the discharge nozzle 6permitting the liquid to drop from the reservoir 3 on to the upper endof the member 17 The liquid flows down the member 17 in a thin film intothe cup 34. During its passage down the member 17 the liquid isthoroughly acted upon by the atthe cup 34 and from the cup 34 to thereceptacle 18. If the member 17 is provided .with the element 20 the cup34 is dispensed with. If the liquid during its passage down the member17 loses its color, the atmosphere contains a dangerous amount ofcarbonic acid gas, or carbon monoxid gas, or sulfureted hydrogen gas. Ifthe liquid does not lose its color before it reaches the cup 34 or theelement 20, the atmosphere contains a. little but not a dangerous amountof carbonic acid gas, or carbon monoxid gas, or sulfureted hydrogen gas.

The reservoir 3 disclosed in Fig. 6 of the drawing differs but littlefrom the reservoir disclosed in Figs. 1 and 2 of the drawing, thedifference consisting merely in the provision of the reservoir at itsupper end with a neck 37 and closing the upper end of the reservoir by astopper 38. As in the preferred embodiment of the reservoir, themodified form is provided with a discharge nozzle 39 and a turning plug40.

The fluid may consist of the following elements and prepared in thefollowing manner. Four parts sulfuric acid, five parts phthalicanhydrid, and ten parts carbolic acid are mixed and kept at atemperature of 248 F. for a period of eight or ten hours. The resultingproduct is exhausted with boiling water, and the residue is dissolved indilute sodium hydroxid solution and precipitated with pure acetic acid.The product is then purified by boiling its alcoholic solution withanimal charcoal and by precipitating the filtrate with water. Theamorphous (phenolphthalein) powder which results is dissolved one partin fifteen hundred parts of ethel alcohol at a temperature of 70 andapproximately 1/800 of a grain of potassium hydrate in an aqueoussolution is added, producing a liquid possessing a pink color whichdisappears when subjected to the action of carbonic-acid gas.

From the foregoing description, taken in connection with theaccompanying drawing, it should be apparent that I provide a devicewhich is admirably adapted for the purpose for which it is intended,that the device is simple, durable and eflicient of construction, andthat the device may be manufactured and sold at a comparatively lowcost.

Changes in the form, proportlons and minor details of construction maybe made within the scope of the claim without departing from the spiritor sacrificing any of the advantages of the invention.

Having thus described the invention, what 5 I claim is Copies of thispatent may be obtained for a liquid spreading member secured to theceptacle secured to the bracket board below the member.

In testimony whereof I affix my signature in presence of two witnesses.

WALTER STUART LEEOH. Witnesses:

W. F. WILLIAMS, CARL O. KNUTSON.

five cents each, by addressing the "Commissioner of Patents. Washington,I). G.

bracket board below the reservoir, and a re-

